I just realised I had fallen into a small trap. We have been so busy talking about the ESL effect that it was forgottem the ESL is a value of inductance, not impedance that is correctly termed reactance Xl.

So the impedance Z of a capacitor is a composite of R (ESR) + Xl + Xc

Xl = 2Pi x f x L where f =frequency and L =inductance

ESL is an inductance.

It should also be realised that the values of Xc and Xl do not add directly to R because each is effectively 90 degres out of phase with the value represented by R (ESR). Xc lags and Xl leads so they are in fact opposing values. One will subtract from the other. At a resonant frequency Xc = Xl so they cancel out leaving only ESR and the lower the value of ESR the higher the Q value and the more ringing or damped oscillation.